VB.net Encryption Question

[Peter]

Assuming a program correctly impliments Rijndael Encryption....

While using Rijndael 256 bit encryption in vb.net,
if a hacker where to be able to compromise the IV (vector) pattern,
how much would that degrade the security of the encryption?

Would it be a 50% loss? Would it be brute force breakable in less than 6 months?

-Peter

 

[Steven Campbell]

It will allow the attacker to tell if a particular piece of data (already in
their possession) is the one that was encrypted. It does not weaken the
encryption.

In any case, there is no reason that the IV should be compromised, because
it is a random piece of data that is used only at the time of encryption,
and thrown away after its use.


~Steve